A ram-side ejector mechanism shown in the German Pat. No. DE-PS 28 27 561 includes a rotating cam disk pivotally mounted on a machine frame and driven by a gear unit from the crank shaft. The angle lever actuating the ejector pin is supported on the ram executing the working or forming stroke. Constant displacement of the centers of rotation of the angle lever and the cam disk results from the stroke movement of the ram in this known assembly. Thus, an extended cam disk, with which the curve execution, according to the path-time law, for the ejecting movement is taken into account to balance the displacement of the centers of rotation as a result of the ram stroke.
This configuration results in a transfer of the deteriorating transfer angle known from gear technology and the disadvantages resulting therefrom. Such a known ejector mechanism cannot be used on forming machines with ram adjustment because the basic positions of the bearing distances of the angle lever on the ram and on the cam disk on the machine frame alter or change with respect to each other when the ram is adjusted. This results in an alteration of the actuation of the ejector according to the path-time law.
Furthermore, a known ram-side ejector mechanism has an expelling movement effected by a rotating cam disk which is supported together with the angle lever on the ram. The driving mechanism for the cam disk is also situated on the ram executing the stroke. A coupling rod is disposed between the crank or eccentric drive for the ram and the gear unit for the cam disk arranged in a parallel fashion to this drive.
This prior art construction is very expensive and, with the same rotational direction as the main drive, causes additional inertial forces, which results in an uneven operation particularly at high stroke frequencies. Such a known ejector system cannot be used on machines with ram adjustment without an alteration of the path-time law for the ejector, as with ram adjustment, the drive system for the ejector connected in parallel is displaced opposite the machine drive. The coupling rod adopts with this a sloping position which results in rotation of the ejector drive opposite the press drive and this produces a phase displacement for the ejector stroke.